President Nelson, from the recent General Conference said:
A nonbeliever might say that faith is for the weak. But this assertion overlooks the power of faith. Would the Savior’s Apostles have continued to teach His doctrine after His death, at the peril of their lives, if they had doubted Him? Would Joseph and Hyrum Smith have suffered martyrs’ deaths defending the Restoration of the Lord’s Church unless they had a sure witness that it was true? Would nearly 2,000 Saints have died along the pioneer trail if they did not have faith that the gospel of Jesus Christ had been restored? Truly, faith is the power that enables the unlikely to accomplish the impossible.April 2021 General Conference
Let assume that Joseph and Hyrum were martyrs . Does the fact that somebody dies for their beliefs make that belief true? That is what I think Pres Nelson is implying. That seems to be a common theme lately. In a recent devotional to the YSA of East Africa, Elder Holland closed with a testimony based around the idea that Joseph Smith and Hyrum Smith would not have gone to their grave for a cunningly devised fable. He is implying that their death in Carthage Jail was a proof of the truthfulness of Joseph’s work and the church he founded.
But if we agree with this premise, and apply this logic to others that died for their beliefs, it opens a whole can of worms. Lets start with the hijackers on 9/11. Are they martyrs? Does dying make what they believed true? Would they have suffered a martyrs death defending their beliefs unless they had a sure witness that it was true? Would they have gone to their grave for a cunningly devised fable?
I could go on and on naming martyrs, both famous and infamous. The number of suicide attacks has increased greatly since the year 2000, with about 300-400 each year. When somebody dies for their cause, it does not prove the truth of their claims, but that they were sincere.
Obviously there is a difference from intentionally meaning to die in a suicide bombing, and being killed for what you believe. So maybe the example of the hijackers above is not a fair comparison? This Catholic writer seems to believe suicide bombers are not martyrs
False “martyrdom” is usually planned, often the result of months of calculated evil. True martyrdom is usually unplanned, but instead an instinctive response made possible by living a life of virtue.
False “martyrdom” is a single event, with the only relevant action in a false martyr’s life being the circumstances surrounding their death. True martyrdom is usually the culmination of daily acts of dying to self in smaller ways.
False “martyrdom” involves using your body as a weapon. True martyrdom often involves using it as a shield.The Catholic Weekly, 7/21/16
Contrary the the Catholic argument, Fair Mormon, in defending Joseph Smith, admits that “martyrs can die for worthy or ignoble causes, but this makes them no less martyrs.”
So where is my logic wrong? I’m I reading too much into Pres Nelson’s and Elder Holland’s words? Are they allowed some hyperbole because of their position in the church, so it should be expected? Is there a better way to talk about Joseph Smith’s death without implying that anybody that dies for that they believe must have the truth?
 Not everyone believes Joseph Smith was a martyr, due to the fact that he fought back with a pistol. See a contrary view here.